Not a zoo vet at the moment, but I've had the same dilemma in the past. What you need to realize is as a zoo veterinarian, your day to day job will be clinical. The conservation side of zoos is their breeding programs/species survival, providing funds and/or personnel to conservation programs, and occasionally reintroducing animals. Many zoos will send their veterinarians or keepers into the field to assist or teach other professionals. I've seen programs involving animal health checks and diet recommendations for elephants to large scale flamingo catch-ups for research. A zoo looking for a veterinarian will be concerned with you're clinical skills first, then maybe you conservation potential.
If I were you I'd look at every single course and, if you can, skim over the syllabi. When I looked into the wildlife major at my university I realized it had quite a few courses I didn't want to take and/or that were useless to me. Have you considered becoming a biology major? I found that many of the courses I would have wanted to take I could count towards my bio major anyway, plus all of my math, chem, microbiology ect was covered as well. Then I could take the few courses that I thought were useful without worrying about the major/minor in wildlife.
Ornithology, mammology, herptology, ect could be really useful if you manage to retain the information in the long run. Also, if you have a passion for wildlife, you might find many of the courses interesting, which goes a long way in preventing burn out. Personally, I hate plants, so plant identification, botany, plant toxicology, and even soil science would make we want to gouge out my eyes. In the end I would just evaluate what the course offers you as person or you as a future veterinarian. I doubt when you apply for a job a highering committee will be incredibly impressed with an undergraduate minor. I personally think it's like a veterinary school being impressed by you're course selection in high school; I'd imagine they'd only pay attention to a masters or PhD. Have you tried getting in contact with the currator or veterinarian at you're last job? They can provide a lot more insight than anyone on here can. Even if yours was a small zoo, they'll know people and how the politics work, its a really small world out there 🙄.
